Hyaluronic acid is a linear polymeric polysaccharide binding to β-D-N-acetylglucosamine and β-D-glucuronic acid alternately. Hyaluronic acid is distributed in connective tissues of mammals and otherwise prepared by isolation and extraction from crest and umbilical cord of chicken, etc. or by fermentation using microorganisms such as Streptococcus. 
In addition, since hyaluronic acid is contained in a human body, has excellent biocompatibility, and shows various medicinal effects primarily including moisture retaining action, it is attracting attention as a natural material in the medical and cosmetic fields. In addition, hyaluronic acid gel is excellent in handleability and very useful in the medical and cosmetic fields.
Although the hyaluronic acid gel is usually prepared by crosslinking hyaluronic acid through chemical modification (Patent Documents 1 to 3), the crosslinked hyaluronic acid chemically modified is not a natural hyaluronic acid itself. Also, although manufacturing methods for hyaluronic acid gel using acids are known (Patent Documents 4 and 5), they are unsuitable for manufacturing hyaluronic acid gel in a form of a gel sheet or the like which takes complex processes and is required for the medical and cosmetic fields. In addition, since such gel is poorly water-soluble, hyaluronic acid is not dissolved, and thus they are unsuitable as gel used in the cosmetic field aimed at actions of the hyaluronic acid on the skin for providing moisture and tension to the skin.
Recently, scientific effectiveness of skin heating as a countermeasure to wrinkles is known and attracting attention. As cosmetics for increasing a temperature of skin, cosmetics which generate heat by mixing a polyhydric alcohol such as glycerin with water to provide hyperthermic effects have already been known (Patent Documents 6 and 7). However, these cosmetics are to be heated by mixing a polyhydric alcohol-containing preparation with a water-containing preparation and then applied to skin in using, and thus the handling is complicated.
A cosmetic which makes skin absorb CO2 gas to improve bloodstream is also known (Patent Document 8). However, use of this cosmetic is also complicated because the cosmetic is to be applied to the face while CO2 gas is generated by mixing a carbonate-containing preparation with an acidic components-containing preparation in using.